All the reversing radars now used for the cars are mounted with special devices by the professionals. They are mounted at a rear bumper of a vehicle. Generally, when they are mounted, they are embedded and an opening has to be made at the mounting place. Furthermore, they can only be mounted correctly and quickly under the professional instructions. In this way, the former car body is destroyed and also, it is difficult to mount the radar. The requirements on the professionals and devices for mounting radars are very high, the orientation is fixed and it is inconvenient to mount them. An ultrasonic sensor and a camera adopted by a vehicle reversing radar need to be arranged and matched reasonably and the mounting angle and position of the camera will influence the use effects of the vehicle reversing radar alarm. In another aspect, the mounting angle of the camera is required to change due to different roads conditions; otherwise, thereby the safety for vehicle reversing is influenced directly.